1. Field of the Invention
This invention relates to personal care products, and, more particularly, to skin and hair care compositions containing a high purity adduct of castor oil and a cyclic carboxylic acid anhydride, which provides a substantive skin feel for the user, and to a method for making such useful adducts with no free acid anhydride therein.
2. Description of the Prior Art
Reaction products of castor oil and dehydrated castor oil with maleic anhydride have been disclosed in the literature. However, they usually involve other components in the reaction mixture which are present to provide the product with suitable properties for use, for example, as hardening agents for epoxy resins, or for leather fat liquoring, or as emulsifiers for the polymerization of vinyl chloride and other aqueous polymer compositions, and as lubricants for rolling mills. For example, SU 445688, published Feb. 26, 1975, described paint compositions containing the reaction product of castor oil and maleic anhydride having a substantial amount of free maleic anhydride, particularly, about 1-4%; and DE 3202408, published Aug. 4, 1983, disclosed the use of castor oil and cyclic anhydride adducts as flexibilizing agents for epoxy resins.
Accordingly, it is an object of the invention to provide a high purity adduct of castor oil and a cyclic carboxylic acid anhydride characterized by the absence of free acid anhydride, and a process for making such advantageous adduct, which is carried out with no significant side reactions.
Another object of the invention is to afford personal care products, particularly for skin care, which provide a highly substantive skin feel, as well as moisturization benefits, and hair care, particularly hair conditioning, in both leave-on and rinse-off applications, which products include a high purity adduct of castor oil and carboxylic acid anhydride having no free acid anhydride.
These and other objects and features of the invention will be made apparent from the following description thereof.